A conventional seed planter implement includes a plurality of seed planter row units commonly mounted to a elongated tool bar or the like that is pulled across a field by a tractor or other suitable off-highway machine. It is not uncommon to mount as many as 24 seed planter row units in laterally spaced side-by-side relation relative to each other behind the tractor. The purpose of each seed planter row unit is to create a furrow having an accurate planting depth and into which a seed is deposited for germination and with reasonably accurate spacing being provided between consecutive seed deposits.
Accordingly, each seed planter row unit typically includes a furrow forming mechanism as part thereof. The furrow forming mechanism of each seed planter row unit conventionally includes a pair of rotatably mounted, generally flat, disk openers that substantially contact each other where the disks enter the ground and diverge apart rearwardly and upwardly. The disks are rotatably supported on a frame which is connected to a tool bar by a parallel support linkage so that the frame is maintained in a generally horizontal position parallel to the ground despite varying ground contours. A spring arrangement extends between the upper and lower links of the parallel linkage. The springs apply varying amounts of upward or downward pressure to the linkage arrangement thereby varying the force applied to the disks of the furrow forming mechanism to affect proper penetration of the soil.
Co-assigned U.S. Pat. No. 4,744,316 granted to D. Lienemann et al. was developed and designed to facilitate furrow forming under different soil conditions. The patented apparatus comprises a furrow forming mechanism including a pair of springs that are independently connected to a support transversely extending between longitudinally extending links of a linkage assembly used to connect a frame of the row unit to a tool bar. To satisfy different soil conditions, each spring on each seed planter row unit required independent and separate manual adjustment through use of a wrench or other form of tool so as to produce a furrow of generally equal depth. Accordingly, in those seed planter configurations embodying up to 24 row units, the operator was required to manually and independently adjust up to 48 different springs each time the spring force on the furrow forming mechanism required change to accommodate differences in soil conditions. Understandably, this involved a labor intensive and time consuming process.
The above mentioned apparatus furthermore allowed movement of the support between different settings. Each support setting allowed a predetermined range of spring forces to be applied by the springs to the furrow forming mechanism. A pair of manually operated locking pins transversely extended from opposite ends of the support and combined with longitudinally spaced holes provided in the links to releasably fix the support in a selected and adjustable position. The manually operated pins are disposed for manual engagement on the same side of the support as the spring adjustment mechanisms associated with each row unit. Accordingly, adjustment of either the springs or the support on each row unit was complicated by providing both manual adjustments in a common plane.
Movement of the support to an adjusted position was also complicated by the attachment of each of the springs to the support. That is, when the manually operated locking pins were released from their cooperative and releasable locking engagement with the linkage assembly, the springs tend to displace the support relative to the links of the linkage assembly thus complicating re-engagement of locking pins thereby frustrating the operators attempt to affect adjustment of the furrow forming mechanism.
Thus, there is a need and a desire for a seed planter row unit that is provided with a furrow forming mechanism that allows the pressure setting of the furrow forming mechanism to be quickly and easily adjusted without the use of tools.